Run compilemessages command to keep .mo files in sync

[SupraSummus]

Problem

Some locales are not working properly when this package is installed from pypi. This is caused by stale .mo files. For example Polish translation .mo file is out of sync since 4d3c9f2

Solution

I've added compilemessages command to the makefile. It makes it harder to forget to update mo file. I've ran the command to sync mo files.

There is another possible solution and that is to remove .mo files from the repository and generate them during build/release time. It seems elegant as there are no binary files in the repo. This approach seems less standard in python ecosystem, however.

[matthewhegarty]

Thank you for this @SupraSummus. I made a minor changes to the Makefile to remove a deprecation warning. Feel free to add your name to AUTHORS.

[coveralls]

Coverage remained the same at 98.063% when pulling 01b704d on SupraSummus:locale into 97a9232 on django-import-export:main.

[manelclos]

Hi, I'm ok with merging the PR as it is now. I strongly agree with @SupraSummus about not keeping the binary (and generated!) files in the repo, there is no easy way to check they are ok. Generating them at build/release time looks more sensible to me. @matthewhegarty what do you think?

[matthewhegarty]

Yes I did wonder about that myself, and I looked into it. Opinion is divided, but I checked, and both Django and Django Rest Framework store their .mo files in the repository. This issue has also been discussed by the Django maintainers, and they decided to keep the .mo files in the repo. Based on that, personally I am OK with it.

I was going to write up a process whereby when it comes to releasing, we create a new PR which has the changelog.rst changes in, and also as part of this PR the new make messages command should be run. This should help to ensure that they don't slip out of date again.

[manelclos]

Awesome, let's keep them then.